#include<iostream>
#include<thread>
#include<mutex>
std::mutex mtx;
void case0();
int main(){
    auto PrintAlpha=[](bool upper,unsigned times=100){
        int offset=upper?0:'a'-'A';
        for(unsigned i=0;i<times;++i){
            for(char b='A';b<='Z';++b){
                std::cout<<static_cast<char>(b+offset);
            }std::cout<<std::endl;
        }
    };
    return 0;
}
void case0(){}